Paper separation structure

ABSTRACT

A paper separation structure includes: an actuating unit being selectable to generate a forward and reverse actuating torque (T); a one-way actuator connected to said actuating unit and being able to break the connection of said actuating unit while said actuating unit generates a reverse actuating torque (T); a breaking unit having a threshold of breaking torque (TL 1 ), and said braking torque (TL 1 ) set lower than said actuating torque (T); and a separating roller connected to said one-way actuator and said braking unit to receive said actuating torque (T) and said braking torque (TL 1 ). With the combination of components mentioned above, the paper separation structure of the present invention has a plurality of torque thresholds for paper separation and can switch between active and passive separation modes according to requirements.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is based on, and claims priority form, Taiwan Patent Application No. 108202040, filed Feb. 18, 2019, the disclosure of which is hereby incorporated by reference herein in its entirety.

BACKGROUND OF THE INVENTION 1. Field of the Invention

This invention relates to a paper separation structure, especially to a paper separation structure having a plurality of torque thresholds for paper separation, and switchable between active and passive separation modes according to requirements.

2. The Related Art

In order to prevent the document overlaps as picked up, a paper separation structure will be arranged next to the pick-up module in the automatic document feeder. Conventional paper separation structures could be sort into active paper separation structure and passive paper separation structure, both will be described below. Referring to FIG. 1A first, FIG. 1A shows a common passive paper separation structure which stops documents being double fed entering the feeding path with a friction pad 53 arranged next to the feed roller 50, and to achieve the effect of separating documents.

FIG. 1B shows another conventional passive paper separation structure which includes a separating roller 51 connected with a torque limiter 54. Said separating roller 51 stays still while documents being fed in, and if it only feeds a single document at once, said separating roller 51 would roll with the document because the transmitting force that pulls the document is greater than the resistance of said torque limiter 54. However, if there is more than one document being fed to said separating roller 51, said separating roller 51 would stay still to stop multi-fed documents. With said design, the paper separation structure can stop multi-fed documents without damaging documents.

Referring to FIG. 1C, FIG. 1 C shows an active paper separation structure comprising a separating roller 51, said separating roller 51 is a motor-driven roller and rotates in the direction reverse to the feed roller 50, and to return the multi-fed documents back to the input tray. The separating roller 51 connects with a driving motor 52. Said active paper separation structure is more accurate in separating documents comparing to the passive paper separation structure. However, the force applied to multi-fed documents can't be control and makes it more likely to damage the document.

Referring to FIG. 1D, to have both advantages of active and passive paper separation structure, there is another paper separation structure that connects said driving motor 52 and said separating roller 51 with an electronic transmission device 55. The torque limit of said electronic transmission device 55 is completely programmable, so the threshold of torque can be adjusted according to the type of documents. While the transmitting torque is lower than the threshold, said electronic transmission device 55 works like a normal transmitting shaft and the paper separation structure separates documents actively. In opposite, when the transmitting torque is greater than the threshold the electronic transmission device 55 would break the link and make said separating roller 51 idling. The paper separation structure separates documents passively currently. Said electronic transmission device 55 can adjust the transmitting torque more precisely corresponding to different types of document, however, it also costs more.

SUMMARY OF THE INVENTION

The objective of the present invention is to provide a paper separation structure to overcome the lack and defects in the conventional document feeding structure.

To achieve said objective, the present invention discloses a paper separation structure includes: an actuating unit being selectable to generate an actuating torque (T) in forward and reverse direction; a one-way actuator connected to said actuating unit and being able to break the connection of said actuating unit while said actuating unit generates the reverse actuating torque (T); a breaking unit having an upper limit of breaking torque (TL1), and said upper limit of braking torque (TL1) set less than said actuating torque (T); and a separating roller connected to said one-way actuator and said braking unit to receive said actuating torque (T) and said braking torque (TL1).

In a preferred embodiment, wherein said breaking unit is a first torque limiter, of which one end is secured and the other end is connected to said separating roller.

In a preferred embodiment, wherein among said separating roller, said one-way actuator, and said breaking unit further arranged a transmission unit which comprising a first transmitting gear and a second transmitting gear meshed to each other, wherein said first transmitting gear connected to both said one-way actuator and said breaking unit for receiving said actuating torque and said braking torque, and said second transmitting gear connected to said separating roller for transmitting the mixed breaking torque mixed with said actuating torque and said braking torque to said separating roller.

In a preferred embodiment, wherein said actuating unit is an electronically controlled motor.

In a preferred embodiment, wherein said breaking unit is a first torque limiter, of which one end is secured and the other end is connected to said transmission unit.

In a preferred embodiment, wherein a second torque limiter is further disposed between said separating roller and said transmission unit, and said transmission unit transmitting actuating torque to said separating roller through said second torque limiter.

In a preferred embodiment, wherein the upper limit of the braking force that said actuating unit provided by the internal resistance is (Tm), and the upper limit of the transmission force provided by said second torque limiter is (TL2), and wherein (Tm)+(TL1)>(TL2), (TL2)>(TL1).

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be apparent to those skilled in the art by reading the following description, with reference to the attached drawings, in which:

FIG. 1A is a schematic diagram that shows a conventional passive paper separation structure.

FIG. 1B is a schematic diagram that shows another conventional passive paper separation structure.

FIG. 1C is a schematic diagram that shows a conventional active paper separation structure.

FIG. 1D is a schematic diagram that shows another conventional active paper separation structure.

FIG. 2 is a schematic diagram that shows a paper separation structure in the first embodiment.

FIG. 3A is a schematic diagram that shows the active separation operation of said paper separation structure shown in FIG. 2.

FIG. 3B is a schematic diagram that shows the passive separation operation of said paper separation structure shown in FIG. 2.

FIG. 3C is a schematic diagram that shows the passive separation operation of said paper separation structure shown in FIG. 2.

FIG. 4 is a schematic diagram that shows a paper separation structure in the second embodiment.

FIG. 5 shows an exploded view of said paper separation structure shown in FIG. 4.

FIG. 6A is a schematic diagram that shows the active separation operation of said paper separation structure shown in FIG. 4.

FIG. 6B is a schematic diagram that shows the passive separation operation of said paper separation structure shown in FIG. 4.

FIG. 6C is a schematic diagram that shows the passive separation operation of said paper separation structure shown in FIG. 4.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

In order to describe the technical contents, structural features, purpose to be achieved and the effectiveness of the present invention, the detailed description is given with schema below.

Referring to FIG. 2, this diagram shows the main structure of the present invention, it comprises an actuating unit 10 which is selectable to generate an actuating torque (T) in forward and reverse direction; a one-way actuator 11 that connects to said actuating unit 10 for breaking the link while said actuating unit 10 generates a reverse actuating torque; a breaking unit 20 having an upper limit of breaking torque (TL1) which is lower than the actuating torque (T); and a separating roller 40 connected with said one-way actuator 11 and said breaking unit 20 for combining said actuating torque (T) and said braking torque (TL1) so as to export a mixed torque (Tmix).

Because said mixed torque (Tmix) exported to documents is mixed by said actuating torque (T) and said breaking torque (TL1), the value of mixed torque (Tmix) can be adjusted by adjusting said actuating torque (T). Thus, the paper separation structure in this embodiment can switch between active and passive document-separating mode and adjusts threshold of torque to fit different document feeding situations.

Referring to FIG. 3A to FIG. 3C, in order to describe clearly and avoid misunderstanding, the word “forward” in this article is not a physical direction such as clockwise or counter-clockwise, but defined as a direction that makes said separating roller 40 separates document actively, and “reverse” is the direction opposite to “forward”. Furthermore, in all the diagrams of this patent specification, the forward is illustrated as a clock-wise pattern and the reverse is illustrated as a counter-clockwise pattern; the actuating torque in forward direction is marked as (T) and the actuating torque in reverse direction is marked as (−T).

FIG. 3A shows the process of active document separating, in this case, said actuating unit 10 generates a forward actuating torque (T) (illustrated as a straight arrow, and length as its value), said actuating torque (T) being transmitted to said separating roller 40 via said one-way actuator 11. Meanwhile, said breaking unit 20 applies a braking torque (TL1) to said separating roller 40 (illustrated as a wavy arrow, and length as its value). Said actuating torque (T) and said braking torque (TL1) are mixed within said separating roller 40 and because the value of said braking torque (TL1) is smaller than the value of said actuating torque (T), said separating roller 40 exports a forward mixed torque (Tmix) eventually, and said separating roller 40 separates documents actively under said forward mixed torque (Tmix).

In FIG. 3B, it shows the process of passive document separating. In this case, said actuating unit 10 idles, so the total output torque is zero, but the inner resistance of said actuating unit 10 still provides a small breaking torque (Tm) to said one-way actuator 11. Meanwhile, said breaking unit 20 still provides a braking torque (TL1) to said separating roller 40. Said breaking torque (Tm) and said braking torque (TL1) are mixed within said separating roller, and as a result, said separating roller exports a reverse mixed torque (Tmix) which is a breaking torque. Thus, said separating roller 40 separates documents passively under said mixed torque (Tmix), and the value of said mixed torque (Tmix) equals to (Tm)+(TL1).

FIG. 3C shows another process of passive document separating, in order to deal with a different type of paper such as thin paper, the upper limit of said mixed torque (Tmix) must be lower than what it is shown in FIG. 3B. To lower the mixed torque (Tmix) applied to said separating roller 40 in advance, said actuating unit 10 in this embodiment provides a reverse actuating torque (−T) to said one-way actuator 11 and cause said one-way actuator idling to cut off the link to said separating roller 40. Meanwhile, said breaking unit 20 still provides a braking torque (TL1) to said separating roller 40. Because said one-way actuator 11 is idling, the total torque provided by said one-way actuator 11 is zero, so the mixed torque (Tmix) equals to the breaking torque (TL1) provided by said breaking unit 20. In summary, with all the elements described above, the paper separation structure in the present invention can switch between active and passive document separating mode and adjust the resistance in passive document separating mode according to the type of documents.

Referring to FIG. 4 and FIG. 5 now, it shows another paper separation structure in a second embodiment. As shown in FIG. 4 and FIG. 5, said paper separation structure is constructed with gears, torque limiters, and one-way actuators 11. Said actuating unit 10 in this embodiment is an electronically controlled motor 12 which is controllable to rotate forward and reverse. The maximum torque output of said electronically controlled motor 12 is (T) and the braking torque provided by inner resistance while idling is (Tm). Between said one-way actuator 11 and said breaking unit 20 placed a transmission unit 30 which connects said one-way actuator 11 and breaking unit 20 to receive and mix said actuating torque and breaking torque and further exports to said separating roller 40.

In the second embodiment, said transmission unit 30 is set to a gear set which comprises a first transmitting gear 31 and a second transmitting gear 32 meshed with each other. Said first transmitting gear 31 connects to both said one-way actuator 11 and said breaking unit 20 for receiving said transmitting torque (T) and said braking torque (TL1). Said breaking unit 20 is a first torque limiter 21, of which one end is secured and the other end is connected to said transmission unit 30. Therefore, if the torque transmitted to said transmission unit 30 is smaller than the upper limit of breaking torque (TL1) of said first torque limiter 21, said transmission unit 30 would stop rotating due to the limit of said first torque limiter 21. With the structure of said transmission unit 30, the reduction ratio and the torque ratio can be adjusted to make the structure design of said paper separation structure more flexible.

In this embodiment, a second torque limiter 41 is arranged between said separating roller 40 and said transmission unit 30 for transmitting mixed torque (Tmix) to said separating roller 40. Said second torque limiter 41 also has an upper limit of transmitting force (TL2) which meets the following conditions: Tm+TL1>TL2, TL2>TL1.

There is one thing has to be mentioned, for simplifying the diagram and the situation, said first transmitting gear 31 and said second transmitting gear 32 has been simplified to a gear set with gear ratio equals to one; said gear set has been set among said one-way actuator 11, said breaking unit 20 and said separating roller 40; and there is no other reducer being set between said transmission unit 30 and said separating roller 40 in this embodiment. Which results in the original torque and the breaking torque generated by actuating unit 10, first torque limiter 21 and second torque limiter 41 are not changed or multiplied during the transmission, and the original torque/breaking torque and final torque/breaking torque equals to one. However, said gear set could be set with various types or quantities of gears to fit the needs of different gear ratio or transmitting directions in practice. Therefore, the position and structure of said transmission unit 30 should not be limited by this embodiment, and the actuating torque, breaking torque or other transmitting force listed above and below are all referred to the output torque/braking force, of which the value is multiplied by said transmission unit 30.

Referring to FIGS. 6A to 6C, it shows the paper feeding process in the second embodiment. In FIG. 6A, the state of active paper feeding is shown. Said actuating unit 10 outputs a forward actuating torque (T) (illustrated as a straight arrow, and length as its value), the actuating torque (T) being transmitted to said transmission unit 30 through said one-way actuator 11, and said breaking unit 20 provides a braking torque (TL1) to said transmission unit 30 (illustrated as a wavy arrow, and length as its value). Since the upper limit of the braking force (TL1) is less than the actuating torque (T), the transmission unit 30 exports a forward mixed torque (Tmix) eventually, and said separating roller 40 separates documents actively under said forward mixed torque (Tmix).

Moreover, since a second torque limiter 41 is further disposed between said separating roller 40 and said transmission unit 30, said paper separation structure in the second embodiment can also prevent the paper separation resistance from being excessive during the active paper separation process. The mixed torque (Tmix) outputted by the transmitting unit 30 is limited by the upper limit (TL2) of said second torque limiter 41, so that said separating roller 40 rotates forward to separates paper in casual states, but slips with the paper to prevent the paper from being damaged if an abnormal state such as a paper jam occurs and makes the resistance greater than the threshold of said second torque limiter 41.

In FIG. 6B, the state of passive paper feeding is shown. in FIG. 6, said actuating unit 10 idles, so the total output torque is zero, but the inner resistance of said actuating unit 10 still provides a small breaking torque (Tm) to said one-way actuator 11. Meanwhile, said breaking unit 20 still provides a braking torque (TL1) to said transmission unit 30. Said breaking torque (Tm) and said braking torque (TL1) are mixed within said transmission unit 30, and as a result, said transmission unit 30 exports a reverse mixed torque (Tmix) which is a breaking torque, and the value of said mixed torque (Tmix) equals to (Tm)+(TL1).

However, since the braking torque (Tm) provided by the internal resistance of said electronically controlled motor 12 is not always a fixed value, it makes said mixed torque (Tmix) variable. To avoid that, the mixed torque (Tmix) supplied to said separating roller 40 is further filtered by said second torque limiter 41 and limited to the upper limit of torque (TL2) of said second torque limiter 41. In result, said separating roller 40 separates documents passively under said limited mixed torque (TL2).

In FIG. 6C, shows another process of passive document separating, in order to separate paper with different characteristics, the upper limit of said mixed torque (Tmix) must be lower than what it is shown in FIG. 6B. To lower the mixed torque (Tmix) applied to said separating roller 40 in advance, said actuating unit 10 in this embodiment provides a reverse actuating torque (−T) to said one-way actuator 11 and cause said one-way actuator idling to cut off the link to said transmission unit 30. Meanwhile, said breaking unit 20 still provides a braking torque (TL1) to said transmission unit 30. Because said one-way actuator 11 is idling, the total torque provided by said one-way actuator 11 is zero, so the mixed torque (Tmix) equals to the breaking torque (TL1) provided by said breaking unit 20.

And because the upper torque limit of said second torque limiter 41 (TL2) is greater than the upper torque limit of said first torque limiter 21 (TL1), said second torque limiter 41 herein functions like a common shaft. With the combination of said components, the paper separation structure in this embodiment can switch between active and passive document separating mode and adjust the resistance in passive document separating mode according to the characteristic of documents.

As described above, with the various combinations of components mentioned above, the paper separation structure of the present invention has a plurality of torque thresholds for paper separation, and can switch between active and passive separation modes according to requirements. 

What is claimed is:
 1. A paper separation structure includes: an actuating unit being selectable to generate an actuating torque (T) in forward and reverse direction; a one-way actuator connected to said actuating unit and being able to break the connection of said actuating unit while said actuating unit generates the reverse actuating torque (T); a breaking unit having an upper limit of breaking torque (TL1), and said upper limit of braking torque (TL1) set less than said actuating torque (T); and a separating roller connected to said one-way actuator and said braking unit to receive said actuating torque (T) and said braking torque (TL1).
 2. The paper separation structure as claimed in claim 1, wherein said breaking unit is a first torque limiter, of which one end is secured and the other end is connected to said separating roller.
 3. The paper separation structure as claimed in claim 1, wherein among said separating roller, said one-way actuator, and said breaking unit further arranged a transmission unit which comprising a first transmitting gear and a second transmitting gear meshed to each other, wherein said first transmitting gear connected to both said one-way actuator and said breaking unit for receiving said actuating torque and said braking torque, and said second transmitting gear connected to said separating roller for transmitting the mixed breaking torque mixed with said actuating torque and said braking torque to said separating roller.
 4. The paper separation structure as claimed in claim 1, wherein said actuating unit is an electronically controlled motor.
 5. The paper separation structure as claimed in claim 3, wherein said breaking unit is a first torque limiter, of which one end is secured and the other end is connected to said transmission unit.
 6. The paper separation structure as claimed in claim 3, wherein a second torque limiter is further disposed between said separating roller and said transmission unit, and said transmission unit transmitting actuating torque to said separating roller through said second torque limiter.
 7. The paper separation structure as claimed in claim 5, wherein the upper limit of the braking force that said actuating unit provided by the internal resistance is (Tm), and the upper limit of the transmission force provided by said second torque limiter is (TL2), and wherein (Tm)+(TL1)>(TL2), (TL2)>(TL1). 